Fable 5.1 Launch Pairs Agentic Gains With a Post-Breach Security Overhaul
Anthropic released Claude Fable 5.1 and Claude Mythos 5.1 on September 1, three months after the first Fable and Mythos models, with Fable 5.1 cutting cache-hit pricing by 75% to $0.25 per million tokens. The launch foll…